The project intends to study, with mouse tumor models, effects of radiation therapy on tumor growth and on concomitant tumor immunity. The objective of the study is to indicate safe and hazardous procedures in radiation treatment of antigenic tumors, and to reveal fundamental aspects of radiation biology and tumor immunity. Areas of investigation are: (1) the immunological basis of tumor enhancing side effects of therapeutic radiation, (2) balances of risk versus benefit when tumor cells exist outside the treated area, (3) dosimetry of therapeutic effects versus dosimetry of impairment of immune factors, (4) repair of radiation damage of immune factors. BIBLIOGRAPHIC REFERENCES: Vaage, J. and Agarwal, S. Serum transfers in repair of radiation-impaired tumor immunity. Proc. Amer. Assoc. Cancer Res. vol. 18, 1977. Vaage, J. A time factor in the success or failure of immune rejection of transplanted tumor. Cancer Res. April 1977.